Casing for electrical apparatus



Feb. 6, 1923.

.11 W. PATCH CASING- FOR ELECTRICAL APPARATUS Filed Nov. 16, 1920Patented Feb. 6, 1923.

UNITED. STATES 1,444,480 PATENT OFFICE.

JAMES PATCH, OF FORT WAYNE, INDIANA, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

CASING FOR ELECTRICAL APPARATUS.

Application filed November 16, 1920. Serial No. 424,488.

To all w/zonzit may concern. Be it known that I, JAMEs W. PATCH, a

citizen of the United States, residing at.

Fort Wayne, county of Allen, State of Indiana, have invented certain newand useful Improvements in Casings for Electrical Apparatusfof which thefollowing is a specification.

My invention relates to casings for elec trical apparatus submerged inoil, such as transformers and the like. 3

More specifically my invention relates to casings provided with deepcorrugations in its side walls in order to increase the cooling capacityof so-called selfcooled'apparatus.

The object of my invention is to provide an improved arrangement ofparts which may be readily and economically manufactured.

The load which may be safely carried by any piece of electricalapparatus is determined by its ability to dissipate properly the heatgenerated while performing under load. This is particularly true of oilsubmerged electrical apparatus such as transformers. In the so-calledself-cooled variety, which depends mainly on radiation to thesurrounding medium or atmosphere to.

effect the necessary cooling, various forms of external radiators havebeen usedto 1ncrease the radiating surface and thereby increase therating of the apparatus.

Another and cheaper way for increasing the radiating surface of thecasing for electrical apparatus is to provide the sidewalls of thecasing with corrugations, an advantageous form of such corrugationsbeing disclosed in U; S. Letters Patent to Moody, No. {13,901. Muchdifficulty howeverhas been egperienced in providing deep corrugationsfor apparatus of large capacity in a cheap and efficient manner; suchcorru"- gations are generally required to be six, eight or more inchesdeep.

,In accomplishing the object of my inven- 'tion I employ corrugatedunits composed of aplurality of convolutionsfsuch units having a specialdevelopment of a character to provide guides for bending. They may alsoI at the same time provide knobs of surplus stock for welding purposes.These units .ing welding edge.

same being braced and reinforced in a novel manner, as will hereinafterappear.

For a more complete understanding of the nature and objects of myinvention reference should be had to the following detailed descriptiontaken in connection with the accompanying drawing in which:

Fig. 1 is a view in front elevation of the top portion of a corrugatedunit from which to construct casings for electrical apparatus accordingto my invention; Fig. 2 is 'a top plan view of the corrugated unit shownin Fig. 1'; Fig. 3 is a fragmentary view of the plane development of anend of my unit; while Fig. 4 is -a fragmentary view mainly in verticalsection of a casing constructed in accordance with my invention.

Referring now to the drawing, 10 denotes a unit ofmy invention shown inperspective as bent to,the desired. form and lying on a surface slightlycurved.

' This unit is shown, as having four con volutions and is made bybending up a piece I of sheared stock 11 developed as shown in Flg. 3which has ends provided with V shaped notches 12, likewise four innumber -to provide the four convolutions in the formed unit.. Betweenthe V shaped notches the stock is cut out to provide a back, the samebein preferabl'y'more deeply cut out at each si e in order to leave aknob or protruding portion as shown at 1,3. Each edge of the shearedblank formed as shown in hafif a back along the edge plus a portionadapted to be bent up to provide an upstand- The welding edges are 3 iscut to provide the development of Y adapted to be bent up sharply alongthe dotted lines If the convolution as a being similarly bent up fromsuch edge along the dotted line indicated at 15. The crest of the corruation is formed by bendlng along the dotte line 16 whichextends from,the bottom of a V, notch at the top of the blank to the bottom of one atthe lower end, the

bending of course on the line 16 being in an opposite direction to thatalong lines 14 and 15 and not very sharp. The other backs are formed bybending along the lines indicated at.15'.

Units when thus bent along the longitudt .nallines 14, 15, 16, etc, areready to have the ends of the convolutions closed. ends may be closed byany suitable drawing and pinching device which provides ofiset edges,asshown at 20, that may be-closed by welding, brazing and the like.

Units with ends closed and finished in this manner are adapted to beunited to one another bywelding along their upstanding longitudinaledges shown at 21.

A sufficient number of units having been united in this manner toprovide a tank of the desired perimeter. they are ready to be assembledon-top and. bottom rings 30 and 31 to form a tank as shown in Fig. 4:.The development shown in Fig. 3 is adapted to provide a corrugated unit.when bent as shown in Figs. 1 and 2. which will have its backs and endslyingin a ruled or smooth surface. The now serrated ends of the formedunit 10 will consequent-l fit snugly against the curved surfaces (whichare one species of ruled surface) of the top and bottom rings 30 and 31.

In welding the formed-units to the rings 30 and 31 the knobs 13 becomefused and provide an excess of metal which may be flowed about the weldas needed. This is particularly advantageous when welding thin metalsuch that of which the formed units are made. while relatively thickmetal is employed in the rings 30 and 31. This mode of welding produceswelds along zig- Zag lines about the top and bottom rings,

as the welds are made upover the abutting portions of theC-OIlVOllltlOIlS where they join the rings and then down across the endsof theback portions about the knobs 13. These zig-zag welds brace theunits welded to the rings 30 and 31 and prevent them from being easilypried loose from these rings.

The rings 30 and 31 are further braced and reinforced by the provisionof inwardly projecting stiffening ribs 32, which may be provided bywelding an angle iron about the interior peripheries as shown.

Tank bodies formed. of corrugated units 10 and top and bottom rings 30and 31, as just described, are then ready to be welded or otherwisesecured 'to suitable bases, such as that shown at 35; the tops beingclosed by suitable covers which are not shown.

While I have called the members 30 and 31 rings in the above, it will beunderstood that they need not be circular, but may be oval, ellipticalor other suitable shape.

Having now described an embodiment of my invention which is at presentthe best means known to me for carrying the same into effect, 1 wouldhave it understood that this is merely illustrative and that I do notmean to be limited thereby tothe precise details shown, nor restrictedin the choice of recognized equivalents except as defined in my claimshereunto annexed.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is a 1. A sheet metal casing for electrical apparatus comprisingtop and bottom rings 7 hand this 12th day of November,

and corrugated walls secured therebetween:

along parallel longitudinal lines to providealternate convolut-ions-andflat backs to lie in a ruled surface, said convolutions being drawn{together at their ends to close the same and formed to provide zig-zagwelding edges at the ends of the units.

3. A sheet metal casing for electrical apparatus comprising top andbottom, rings and corrugated walls secured therebetween; said wallsbeing composed.- of units made from sheared blanks having ends formedwith a plurality of spaced V shaped notches, ad acent V shaped notchesbeing separated by an intervening projecting knob. the blank being bentalong parallel longitudinal lines to provide flat backs and {a pluralityof con volutions lying in a ruled surface, sa d con volutions beingdrawn together at their ends to close the same. 7

1. A'sheet metal casing for electrical app a-ratus comprising topandbottom rings and corrugated walls secured therebetween; said rings beingprovided with stiffening ribs and having said walls welded thereto alongz1gzag paths.

5. A. sheet metal casing for electrical ap-, paratus comprising top andbottom rings and corrugated walls secured tlierebetween; said ringshaving angle irons welded lnteriorly about their peripheries to providestiffening ribs therefor and having said walls welded thereto exteriorlyalong zig-zag paths.

6. A sheet metal casing for electrical ap paratus comprising top andbottom rings and corrugated walls secured therebetween; said rings beingprovided with stiffening ribs interiorlyand having said walls composedof units with serrated ends welded thereto exteriorly along pathsfollowing the serrated ends of said units. I

7. A sheet metal casing for electrical apparatus comprising top andbottom rings and along paths following said serrated end I edges.

In witness whereof, I have herepnQtg set my 9 JAMES W.

PATCH.

